The lightweight concrete, which is a “porous” material, has long been recognised as having “limited durability”, according to the LGA. The Government has been aware of public sector buildings constructed with the material since 1994.
2017
The Standing Committee on Structural Safety was asked to investigate the suitability of the material after a school roof collapsed, although it is not clear which school this was.
2018
Another roof collapsed at a Singlewell Primary School in Kent. It happened above the school staff room, also damaging toilets, ICT equipment and an administration area. The collapse prompted Kent Council to write to other local authorities warning them to check for RAAC in their schools.
2019
A structural engineer investigating on behalf of SCOSS began to “frequently” encounter RAAC planks that weren’t fit for purpose and warned all those installed before 1980 should be replaced.
Sounds like one was not identified and collapsed in 2017. Another was Singlewell Primary School in Kent in 2018.
https://www.msn.com/en-gb/news/uknews/the-raac-concrete-ticking-time-bomb-that-schools-were-warned-about-years-ago/ar-AA1g5cDO